Browsing by Author "Somwe P"

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Cross-sectional assessment of tuberculosis and HIV prevalence in 13 correctional facilities in Zambia.
(2021-Sep-27) Kagujje M; Somwe P; Hatwiinda S; Bwalya J; Zgambo T; Thornicroft M; Bozzani FM; Moonga C; Muyoyeta M
OBJECTIVE: To determine the prevalence of tuberculosis (TB) and HIV in 13 Zambian correctional facilities. METHODS: Cross-sectional study. SETTING: 13 correctional facilities in seven of the 10 provinces in Zambia. PARTICIPANTS: All incarcerated individuals were eligible for TB and HIV screening and testing. Of the total study population of 9695 individuals, which represent 46.2% of total correctional population at the beginning of the study, 8267 and 8160 were screened for TB and HIV, respectively. INTERVENTIONS: TB and HIV screening and testing was done between July 2018 and February 2019. PRIMARY OUTCOME MEASURES: All forms of TB, bacteriologically confirmed TB, drug-resistant TB, HIV. RESULTS: Prevalence of all forms of TB and bacteriologically confirmed TB was 1599 (1340-1894) per 100 000 population and 1056 (847-1301) per 100 000 population, respectively. Among those with bacteriologically confirmed TB, 4.6% (1.3%-11.4%) had drug-resistant TB.There was no statistically significant difference in the prevalence of all forms of TB, bacteriologically confirmed TB and drug resistant TB between adults and juveniles: (p=0.82), (p=0.23), (p=0.68) respectively. Of the bacteriologically confirmed TB cases, 28.7% were asymptomatic. The prevalence of HIV was 14.3% (13.6%-15.1%). The prevalence of HIV among females was 1.8 times the prevalence of HIV among males (p=0.01). CONCLUSION: Compared with the study in 2011 which screened inmates representing 30% of the country's inmate population, then the prevalence of all forms of TB and HIV in correctional facilities has reduced by about 75% and 37.6%, respectively. However, compared with the general population, the prevalence of all forms of TB and HIV was 3.5 and 1.3 times higher, respectively. TB/HIV programmes in correctional facilities need further strengthening to include aspects of juvenile-specific TB programming and gender responsive HIV programming.
Effects of implementing universal and rapid HIV treatment on initiation of antiretroviral therapy and retention in care in Zambia: a natural experiment using regression discontinuity.
(2021-Dec) Mody A; Sikazwe I; Namwase AS; Wa Mwanza M; Savory T; Mwila A; Mulenga L; Herce ME; Mweebo K; Somwe P; Eshun-Wilson I; Sikombe K; Beres LK; Pry J; Holmes CB; Bolton-Moore C; Geng EH
BACKGROUND: Universal testing and treatment (UTT) for all people living with HIV has only been assessed under experimental conditions in cluster-randomised trials. The public health effectiveness of UTT policies on the HIV care cascade under real-world conditions is not known. We assessed the real-world effectiveness of universal HIV treatment policies that were implemented in Zambia on Jan 1, 2017. METHODS: We used data from Zambia's routine electronic health record system to analyse antiretroviral therapy (ART)-naive adults who newly enrolled in HIV care up to 1 year before and after the implementation of universal treatment (ie, Jan 1, 2016, to Jan 1, 2018) at 117 clinics supported by the Centre for Infectious Disease Research in Zambia. We used a regression discontinuity design to estimate the effects of implementing UTT on same-day ART initiation, ART initiation within 1 month, and retention on ART at 12 months (defined as clinic attendance 9-15 months after enrolment and at least 6 months on ART), under the assumption that patients presenting immediately before and after UTT implementation were balanced on both measured and unmeasured characteristics. We did an instrumental variable analysis to estimate the effect of same-day ART initiation under routine conditions on 12-month retention on ART. FINDINGS: 65 673 newly enrolled patients with HIV (40 858 [62·2%] female, median age 32 years [IQR 26-39], median CD4 count 287 cells per μL [IQR 147-466]) were eligible for inclusion in the analyses; 31 145 enrolled before implementation of UTT, and 34 528 enrolled after UTT. Implementation of universal treatment increased same-day ART initiation from 41·7% to 74·8% (risk difference [RD] 33·1%, 95% CI 30·5-35·7), ART initiation by 1 month from 69·6% to 87·0% (RD 17·4%, 15·5-19·3), and 12-month retention on ART from 56·2% to 63·3% (RD 7·1%, 4·3-9·9). ART initiation rates became more uniform across patient subgroups after implementation of universal treatment, but heterogeneity in 12-month retention on ART between subgroups was unchanged. Instrumental variable analyses indicated that same-day ART initiation in routine settings led to a 15·8% increase (95% CI 12·1-19·5) in 12-month retention on ART. INTERPRETATION: UTT policies implemented in Zambia increased the rapidity and uptake of ART, as well as retention on ART at 12 months, although overall retention on ART remained suboptimal. UTT policies reduced disparities in treatment initiation, but not 12-month retention on ART. Natural experiments reveal both the anticipated and unanticipated effects of real-world implementation and indicate the need for new strategies leveraging the short-term effects of UTT to cultivate long-term treatment success. FUNDING: National Institutes of Health.
Evaluating InferVision's Computer-Aided Detection (CAD) algorithm for Tuberculosis (TB) screening, Lusaka, Zambia.
(2025) Somwe P; Maimbolwa M; Chiyenu K; Lumpa M; Kagujje M; Muyoyeta M
The objective of this study was to evaluate the diagnostic performance of InferRead DR Chest for tuberculosis (TB) screening in a high HIV and TB burden setting. The study assessed the performance of InferRead DR Chest using anonymized chest X-ray images from an active TB case finding study in Lusaka, Zambia, for individuals aged 15 and older. The Xpert MTB/RIF or MTB culture was the composite reference standard. Performance was evaluated using the Area Under the Receiver Operating Characteristic Curve (AUC), and a binary classification point was selected where the sensitivity aligned with the WHO target product profile for TB screening tools. Of the 1,890 chest X-ray images that met the inclusion criteria, 91.5% of participants reported at least one TB symptom. The median age was 38 years (IQR: 29-47), and 1,186 (62.8%) were male. From the study sample, 449 participants (23.8%) reported a history of previous TB, and 704 (37.2%) were HIV positive. Among the analyzed images, 289 (15.3%) were classified as TB positive based on the composite reference standard test results. The overall area under the curve (AUC) was 0.81 (95% CI: 0.78-0.83). Among individuals with a history of previous TB and those who were HIV positive, the AUCs were 0.71 (95% CI: 0.63-0.79) and 0.77 (95% CI: 0.72-0.82), respectively. At a sensitivity of 90.3% (95% CI: 86.3%-93.5%), InferRead DR Chest achieved a specificity of 39.2% (95% CI: 36.8%-41.7%) at TB score cut point of 0.12. InferRead DR Chest had acceptable performance in our population. Additional training and piloting of InferRead DR Chest in this population is recommended.
Integrating isoniazid preventive therapy into the fast-track HIV treatment model in urban Zambia: A proof-of -concept pilot project.
(2023) Mukumbwa-Mwenechanya M; Mubiana M; Somwe P; Zyambo K; Simwenda M; Zongwe N; Kalunkumya E; Mwango LK; Rabkin M; Mpesela F; Chungu F; Mwanza F; Preko P; Bolton-Moore C; Bosomprah S; Sharma A; Morton K; Kasonde P; Mulenga L; Lingu P; Mulenga PL
Most people living with HIV (PLHIV) established on treatment in Zambia receive multi-month prescribing and dispensing (MMSD) antiretroviral therapy (ART) and are enrolled in less-intensive differentiated service delivery (DSD) models such as Fast Track (FT), where clients collect ART every 3-6 months and make clinical visits every 6 months. In 2019, Zambia introduced Isoniazid Preventive Therapy (IPT) with scheduled visits at 2 weeks and 1, 3, and 6 months. Asynchronous IPT and HIV appointment schedules were inconvenient and not client centered. In response, we piloted integrated MMSD/IPT in FT HIV treatment model. We implemented and evaluated a proof-of-concept project at one purposively selected high-volume facility in Lusaka, Zambia between July 2019 and May 2020. We sensitized stakeholders, adapted training materials, standard operating procedures, and screened adults in FT for TB as per national guidelines. Participants received structured TB/IPT education, 6-month supply of isoniazid and ART, aligned 6th month IPT/MMSD clinic appointment, and phone appointments at 2 weeks and months 1-5 following IPT initiation. We used descriptive statistics to characterize IPT completion rates, phone appointment keeping, side effect frequency and Fisher's exact test to determine variation by participant characteristics. Key lessons learned were synthesized from monthly meeting notes. 1,167 clients were screened with 818 (70.1%) enrolled, two thirds (66%) were female and median age 42 years. 738 (90.2%) completed 6-month IPT course and 66 (8.1%) reported IPT-related side effects. 539 clients (65.9%) attended all 7 telephone appointments. There were insignificant differences of outcomes by age or sex. Lessons learnt included promoting project ownership, client empowerment, securing supply chain, adapting existing processes, and cultivating collaborative structured learning. Integrating multi-month dispensing and telephone follow up of IPT into the FT HIV treatment model is a promising approach to scaling-up TB preventive treatment among PLHIV, although limited by barriers to consistent phone access.
Prevalence and interpretation of Xpert
(2022-Mar-21) Chilukutu L; Mwanza W; Kerkhoff AD; Somwe P; Kagujje M; Muyoyeta M
BACKGROUND: The "trace call" results on Xpert® Ultra indicates extremely low TB levels and may be difficult to interpret. The prevalence of trace results among presumptive TB patients in high TB-HIV infection settings is unknown, as is the significance of divergent "trace call" result interpretations. METHODS: Presumptive TB patients attending a public health facility in Lusaka, Zambia, were prospectively enrolled. Participants underwent several TB investigations, including sputum smear microscopy, Ultra testing, and culture. The diagnostic accuracy of Ultra (culture-based reference) and the number of patients recommended for TB treatment was assessed according to several different interpretation criteria for "trace call" results. RESULTS: Among the 740 participants, 78 (10.5%) were Ultra-positive and an additional 37 (5.0%) had a "trace call" result. The prevalence of trace results did not differ according to HIV status (5.3% vs. 4.8%) or prior TB status (5.6% vs. 4.9%). Differing interpretations of trace results had modest effects on Ultra's sensitivity (range 79.3-82.6%) and specificity (range 94.3-99.2%), but increased the number of patients recommended for treatment by up to 44.9%. CONCLUSIONS: Ultra trace results were common in this setting. The interpretation of trace results may substantially impact TB case yield.
Prevalence of Diarrhoeagenic
(2023-Nov-17) Mwape K; Bosomprah S; Chibesa K; Silwamba S; Luchen CC; Sukwa N; Mubanga C; Phiri B; Chibuye M; Liswaniso F; Somwe P; Chilyabanyama O; Chisenga CC; Muyoyeta M; Simuyandi M; Barnard TG; Chilengi R
Diarrhoea is a major contributor to childhood morbidity and mortality in developing countries, with diarrhoeagenic
Sensitivity and specificity of CRP and symptom screening as tuberculosis screening tools among HIV-positive and negative outpatients at a primary healthcare facility in Lusaka, Zambia: a prospective cross-sectional study.
(2023-Apr-18) Kagujje M; Mwanza W; Somwe P; Chilukutu L; Creswell J; Muyoyeta M
OBJECTIVES: To evaluate the performance of point-of-care C-reactive protein (CRP) as a screening tool for tuberculosis (TB) using a threshold of 10 mg/L in both people living with HIV (PLHIV) and HIV-negative individuals and compare it to symptom screening using a composite reference for bacteriological confirmation of TB. METHODS: Prospective cross-sectional study. SETTING: A primary healthcare facility in Lusaka, Zambia. PARTICIPANTS: Consecutive adults (≥18 years) presenting for routine outpatient healthcare were enrolled. Of the 816 individuals approached to participate in the study, 804 eligible consenting adults were enrolled into the study, of which 783 were included in the analysis. PRIMARY OUTCOME MEASURES: Sensitivity, specificity, positive predictive value and negative predictive value (NPV) of CRP and symptom screening. RESULTS: Overall, sensitivity of WHO-recommended four-symptom screen (W4SS) and CRP were 87.2% (80.0-92.5) and 86.6% (79.6-91.8) while specificity was 30.3% (26.7-34.1) and 34.8% (31.2-38.6), respectively. Among PLHIV, sensitivity of W4SS and CRP was 92.2% (81.1-97.8) and 94.8% (85.6-98.9) while specificity was 37.0% (31.3-43.0) and 27.5% (22.4-33.1), respectively. Among those with CD4≥350, the NPV for CRP was 100% (92.9-100). In the HIV negative, sensitivity of W4SS and CRP was 83.8% (73.4-91.3) and 80.3% (69.5-88.5) while specificity was 25.4% (20.9-30.2) and 40.5% (35.3-45.6), respectively. Parallel use of CRP and W4SS yielded a sensitivity and NPV of 100% (93.8-100) and 100% (91.6-100) among PLHIV and 93.3% (85.1-97.8) and 90.0% (78.2-96.7) among the HIV negatives, respectively. CONCLUSION: Sensitivity and specificity of CRP were similar to symptom screening in HIV-positive outpatients. Independent use of CRP offered limited additional benefit in the HIV negative. CRP can independently accurately rule out TB in PLHIV with CD4≥350. Parallel use of CRP and W4SS improves sensitivity irrespective of HIV status and can accurately rule out TB in PLHIV, irrespective of CD4 count.
Temporal changes in paediatric and adolescent HIV outcomes across the care continuum in Zambia: an interrupted time-series analysis.
(2022-Aug) Bolton-Moore C; Sikazwe I; Mubiana-Mbewe M; Munthali G; Wa Mwanza M; Savory T; Nkhoma L; Somwe P; Namwase AS; Geng EH; Mody A
BACKGROUND: Paediatric and adolescent HIV treatment programmes in sub-Saharan Africa have rapidly expanded and evolved over the past decade. Real-world evidence of how the implementation of new policies over time has affected treatment outcomes is inadequate, but is crucial for guiding the implementation of the next phases of the HIV treatment response for children. We examined how treatment outcomes in Zambia's national paediatric and adolescent HIV treatment programmes have changed over time as new policies were implemented. METHODS: We used data from Zambia's routine electronic health record to analyse children and adolescents living with HIV who were antiretroviral therapy (ART) naive between the ages of 0 and 19 years who were newly enrolled in care between Jan 1, 2011, and March 31, 2019, at 102 health facilities in Lusaka and Western provinces supported by the Centre for Infectious Disease Research in Zambia. Sociodemographic factors, clinical data, facility-level data, and visit history were obtained from the national electronic health record and laboratory systems used in routine HIV care in Zambia. We aimed to characterise the changes in the distribution of the age and sex of new enrolees over time. We used an interrupted time-series design to examine the rates of ART initiation, retention in care, time to ART initiation, and first-line ART regimens among new enrolees across different age strata as they changed over time with the adoption of new ART guidelines in 2014 and 2017. FINDINGS: Between Jan 1, 2011, and March 31, 2019, 26 214 children and adolescents living with HIV who were ART naïve were newly enrolled at one of 102 ART facilities in two provinces in Zambia. Rates of new enrolees increased by 25-35% among children younger than 15 years over time, but by 92·3% between 2011 and 2017 among adolescents, with the largest absolute increase among adolescent girls. Rates of ART initiation increased steadily and in parallel across all age groups from before the implementation of the 2014 guidelines to after the implementation of the 2017 guidelines (<2 years, 42·4% for 2014 and 81·6% for 2017; 2 to <5 years, 39·3% for 2014 and 82·8% for 2017; 5 to <15 years, 49·2% for 2014 and 86·6% for 2017; 15 to 19 years, 52·4% for 2014 and 86·2% for 2017); median time to ART initiation went from 2-3 months to same-day initiation during this same time period. Rates of retention on ART 6 months after linkage saw much smaller improvements over time (<2 years, 35·4% for 2014 and 52·0% for 2017; 2 to <5 years, 40·2% for 2014 and 54·4% for 2017; 5 to <15 years, 46·7% for 2014 and 63·4% for 2017; 15 to 19 years, 40·1% for 2014 and 52·7% for 2017). INTERPRETATION: Improvements in ART initiation occurred largely in parallel across age groups over time, despite universal treatment being implemented at different timepoints for different ages. Although the rates of ART initiation reach high levels, retention on ART was low. This analysis provides a comprehensive examination of how paediatric and adolescent outcomes have evolved over the past decade in Zambia and identifies where more targeted efforts will be needed over the next decade. FUNDING: National Institutes of Health.
The effect of tracer contact on return to care among adult, "lost to follow-up" patients living with HIV in Zambia: an instrumental variable analysis.
(2021-Dec) Beres LK; Mody A; Sikombe K; Nicholas LH; Schwartz S; Eshun-Wilson I; Somwe P; Simbeza S; Pry JM; Kaumba P; McGready J; Holmes CB; Bolton-Moore C; Sikazwe I; Denison JA; Geng EH
INTRODUCTION: Tracing patients lost to follow-up (LTFU) from HIV care is widely practiced, yet we have little knowledge of its causal effect on care engagement. In a prospective, Zambian cohort, we examined the effect of tracing on return to care within 2 years of LTFU. METHODS: We traced a stratified, random sample of LTFU patients who had received HIV care between August 2013 and July 2015. LTFU was defined as a gap of >90 days from last scheduled appointment in the routine electronic medical record. Extracting 2 years of follow-up visit data through 2017, we identified patients who returned. Using random selection for tracing as an instrumental variable (IV), we used conditional two-stage least squares regression to estimate the local average treatment effect of tracer contact on return. We examined the observational association between tracer contact and return among patient sub-groups self-confirmed as disengaged from care. RESULTS: Of the 24,164 LTFU patients enumerated, 4380 were randomly selected for tracing and 1158 were contacted by a tracer within a median of 14.8 months post-loss. IV analysis found that patients contacted by a tracer because they were randomized to tracing were no more likely to return than those not contacted (adjusted risk difference [aRD]: 3%, 95% CI: -2%, 8%, p = 0.23). Observational data showed that among contacted, disengaged patients, the rate of return was higher in the week following tracer contact (IR 5.74, 95% CI: 3.78-8.71) than in the 2 weeks to 1-month post-contact (IR 2.28, 95% CI: 1.40-3.72). There was a greater effect of tracing among patients lost for >6 months compared to those contacted within 3 months of loss. CONCLUSIONS: Overall, tracer contact did not causally increase LTFU patient return to HIV care, demonstrating the limited impact of tracing in this program, where contact occurred months after patients were LTFU. However, observational data suggest that tracing may speed return among some LTFU patients genuinely out-of-care. Further studies may improve tracing effectiveness by examining the mechanisms underlying the impact of tracing on return to care, the effect of tracing at different times-since-loss and using more accurate identification of patients who are truly disengaged to target tracing.
The Incidence and Risk Factors for Enterotoxigenic
(2024-Mar-29) Sukwa N; Bosomprah S; Somwe P; Muyoyeta M; Mwape K; Chibesa K; Luchen CC; Silwamba S; Mulenga B; Munyinda M; Muzazu S; Chirwa M; Chibuye M; Simuyandi M; Chilengi R; Svennerholm AM
This study aimed to estimate the incidence and risk factors for Enterotoxigenic
Tobacco smoking and smokeless tobacco use among people living with HIV in Zambia: Findings from a 2023 National NCD/HIV Survey.
(2025) Zyambo C; Somwe P; Mandyata C; Musukuma M; Bwembya P; Phiri H; Chavula MP; Halwindi H; Zulu J; Mutale W
BACKGROUND: People living with HIV (PLWH) who use tobacco face significant public health risks compared to non-users, including an average loss of 12.3 years of life expectancy. Tobacco use increases the likelihood of non-communicable diseases (NCDs), such as cardiovascular diseases, hypertension, diabetes mellitus, and non-AIDS-related cancers. AIM: This study investigated factors associated with tobacco smoking and smokeless tobacco (SLT) use among PLWH in Zambia. METHODS: Data were obtained from a national cross-sectional survey involving 5,204 PLWH from 193 clinics across Zambia's 10 provinces. Tobacco smoking, SLT use, behavioral patterns, and clinical characteristics were assessed. Logistic regression was used to determine unadjusted (UOR) and adjusted odds ratios (AOR) at a 95% confidence interval (CI). RESULTS: Among the 5,204 PLWH surveyed, 9.7% were current tobacco smokers (21.9% men, 3.7% women), while 1.4% used smokeless tobacco (1.81% men, 1.26% women). In the multivariable analysis, several factors were identified as predictors of tobacco smoking. Male individuals had significantly higher odds of smoking (AOR: 4.81, 95% CI: 3.36-6.90). In contrast, higher educational attainment was associated with lower odds of smoking (AOR: 0.29, 95% CI: 0.16-0.52). Alcohol consumption was associated with an increased likelihood of smoking (AOR: 4.97, 95% CI: 2.93-8.44). Additionally, overweight or obese individuals were less likely to smoke, with adjusted odds ratios of 0.55 (95% CI: 0.35-0.85) and 0.36 (95% CI: 0.17-0.79), respectively. Non-adherence to antiretroviral therapy (ART) was also associated with higher smoking rates (AOR: 1.75, 95% CI: 1.14-2.67). Similarly, several factors were identified as predictors of smokeless tobacco (SLT) use. Individuals with an annual income exceeding 4,000 ZMW had lower odds of using SLT (AOR: 0.31, 95% CI: 0.14-0.73). In contrast, alcohol users exhibited significantly higher odds of SLT use (AOR: 14.74, 95% CI: 1.99-109.02). Furthermore, non-adherence to ART was associated with an increased likelihood of SLT use (AOR: 3.32, 95% CI: 1.54-7.17). CONCLUSIONS: Our findings highlight the urgent need for targeted interventions to reduce tobacco use among PLWH in Zambia. Integrating these measures within the existing healthcare framework can maximize impact. Gender-specific programs addressing unique risk factors, alongside economic empowerment initiatives for low-income females, could help curb SLT use. Additionally, reinforcing ART adherence through tobacco cessation counseling within HIV care settings may lower smoking rates. Given the strong association between alcohol consumption and tobacco use, structured behavioral interventions and support programs should also be prioritized. Strengthening collaborations between health authorities and community organizations can further enhance accessibility and outreach. By embedding these strategies within primary care and ART clinics, Zambia can effectively reduce tobacco use among PLWH, ultimately improving overall health outcomes and strengthening HIV management efforts.